1. Field of the Invention
The present invention relates to a fan shroud assembly.
2. Background of the Related Art
In general, an engine room of a vehicle includes an engine which is a vehicle driving device, a cooling device for preventing overheating of the engine, and an air conditioning device for purifying air of a passenger side inside the vehicle.
A cooling method of the engine of the vehicle is divided into an air-cooling type and a water-cooling type. The water-cooling type engine cooling method is to cool the engine using coolant, which flows along the outer surface of the engine.
The water-cooling type engine cooling device includes a radiator attached to the front of the engine of the vehicle for cooling the coolant of the engine, and a fan assembly attached to the radiator for enhancing heat exchanging efficiency.
The fan shroud assembly generally includes a fan, a driving motor for rotating the fan, and a fan shroud for supporting the fan.
FIG. 1 is a perspective view of a conventional fan shroud assembly equipped with a fan eccentrically mounted, and FIG. 2 is a sectional view taken along the line of I—I of FIG. 1.
As shown in the drawings, the fan shroud assembly 10 includes: a plenum 11 having a first plenum portion 11a of a larger side and a second plenum portion 11b of a smaller side, the first and second plenum portions 11a and 11b being eccentrically mounted corresponding to the front of the radiator by a support structure(not shown); a airflow guide portion 15 formed on an air discharge side of the plenum 11, a fan 14, which has a blade 12 and a band 13 for connecting the outer end of the blade 12, a motor mounting 16 located at the center of the airflow guide portion 15 for mounting of a motor 18; and a stator 17 for connecting the motor mounting 16 and the airflow guide portion 15.
Here, the airflow guide portion 15 is located at a portion where the first plenum portion 11a and the second plenum portion 11b are located at eccentric positions to each other.
As described above, the fan 14 receiving driving power of the motor 18 is rotated, the air passing the radiator is inhaled and guided by the plenum 11, and then, discharged to an engine side(not shown) through the stator 17 of the airflow guide portion 15.
However, according to the prior arts, as the fan 14 is not located at the center of the plenum 11 but biased to one side, in a state in which a connection point P1 between the first plenum portion 11a and the airflow guide portion 15 is equal to the lowermost end of a height BH of the band 13, the first plenum portion 11a is formed straight downwardly, and a height H1 from the bottom B of the plenum 11 to the connection point P1 between the first plenum portion 11a and the airflow guide portion 15 is equal to a height H2 from the bottom B of the plenum 11 to a connection point P1′ between the second plenum portion 11b and the airflow guide portion 15.
Because the height H1 from the bottom B of the plenum 11 to the connection point P1 between the first plenum portion 11a and the airflow guide portion 15 is lower than or equal to the height H0 from the bottom B to the lowermost end of the band 13, the air flow area is reduced, and thereby, the prior art has several problems that airflow is reduced and noise is generated.
U.S. Pat. No. 5,024,267 will be described hereinafter with reference to FIG. 3. U.S. Pat. No. 5,024,267 discloses a cooling apparatus which does not have any band.
As shown in the drawing, a cylindrical portion 21 of a shroud 20 of the cooling apparatus, in which a fan is disposed, is biased to one side as shown in FIGS. 1 and 2.
The shroud 20 has a first plenum portion 22 of a larger side and a second plenum portion 23 of a smaller side as the cylindrical portion 21 is biased to one side.
Here, the height H1 from the lowermost end of the cylindrical portion 21 to the first plenum portion 22 is equal to the height H2 from the lowermost end of the cylindrical portion 21 to the second plenum portion 23.
That is, as in the prior arts of FIGS. 1 and 2, the height H1 from the bottom B of the plenum 11 to the connection point P1 between the first plenum portion 11a and the airflow guide portion 15 is equal to the height H2 from the bottom B to the connection point P1′ between the second plenum 11b and the airflow guide portion 15. Furthermore, also the above prior art has the above problems that the airflow is reduced and noise is generated, as the prior art does not have the band 13 shown in FIGS. 1 and 2.
As another example of the prior arts, U.S. Pat. No. 6,099,247 will be described. Referring to FIGS. 4 and 5, a fan shroud for internal combustion engine according to U.S. Pat. No. 6,099,247 includes an intake manifold 31 attached to one side (in a right direction) of an internal combustion engine 30, and an exhaust manifold 32 attached to the other side (in a left direction) of the internal combustion engine 30, which is an exhaust system part.
A cooling device 33 is mounted in front of the internal combustion engine 30.
The cooling device 33 has a cooling fan 34 attached by a fan shaft 35 to internal combustion engine 30, and a radiator 36 is installed, opposite to the cooling fan 34.
Attached to the radiator 36 is a fan shroud 38, equipped with an airflow guide portion 37 which encircles the cooling fan 34 and is formed as a circle.
Here, the cooling fan 34 is located inside the airflow guide portion 37. To increase cooling air, a clearance C1 between the airflow guide portion 37 and the cooling fan 34, which belongs to a first plenum portion 38a of a larger side of the fan shroud 38, is larger than a clearance C2 between the airflow guide portion 37 and the cooling fan 34, which belongs to a second plenum portion 38b of a smaller side of the fan shroud 38. However, also, U.S. Pat. No. 6,099,247 still has the above problems that the airflow is reduced and noise is generated.
As the cooling fan 34 is rotatably mounted on the fan shaft 35 rotating by directly receiving driving power of the internal combustion engine 30, the cooling fan 34 is vibrated together with the driving internal combustion engine 30. Thereby, the air does not flow uniformly but flows irregularly, and so, the cooling efficiency is reduced.
U.S. Pat. No. 4,213,426, which is another example of the prior arts, will be described hereinafter with reference to FIG. 6.
As shown in the drawing, a shaft 43 rotated by receiving driving power of an engine 42 is attached to a vehicle frame 40 in front of an end of the engine 42 mounted by the medium of a brocket 41.
A hub 44 is fixed to an end of the shaft 43, a number of blades 45 are disposed on the hub 44, and a fan shroud 46 that is integral with the outer tips of the blades 45.
The hub 44, the blades 45 and the fan shroud 46 are vibrated together with the driving engine 42 as they are rotated by receiving driving power of the engine 42. To inhale the vibration, an outer shroud assembly 51 connected with a radiator 50 is attached to the outside of the fan shroud 46, the outer shroud assembly 51 is moved flexibly.
However, the fan shroud assembly according to the prior art cannot flow the air in a uniform direction but flows the air in an irregular direction due to the vibration in spite of the outer shroud assembly 51. Moreover, the fan shroud assembly has a problem in that the air flow is reduced and noise is generated.